todo

* make into functions:
  aref, make-array, vector, uint

* check which places actually need primary-type

* enforce type . named-types layout to type-sets
  assert type is never :void

* unify type & multi-vals in code objects

* make-user-function-obj in make-function.lisp has a daft way of storing the
  return types, we should make it follow the return-set approach. Currently
  I think this is where the return-sets of void are coming from

* make context restriction work with special functions

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* why use def-v-type-class for v-user-function? Switch to defclass?

* low-hanging-fruit: unify labels/flet/labels-no-implicit implementations

* need an across vector loop thing. We can then unroll these loops.
* also add all the arithmatic operators for non number datatypes
* add aref, make-array and array constructors

* add-function to global should remove functiosn that are totally blocked, so match
  on (cons func-name (v-args func)) as only the newsest one will be selected and it slows
  down processing
* merge-compiled needs a new name
* Write tour guide

* read up on setting variables as invariant
* find out what centroid means
* add preprocessor extensions to translate function
* check out _line_ _file_ and _version_ macros from glsl, are they
  used?
* add lisp macros wrappers for this functionality
* how do we handle ARBs?